Official Irish Republican Army

The Official Irish Republican Army (OIRA) was a socialist Irish republican paramilitary group that existed from December 1969 to May 1972. The OIRA sought to unite Northern Ireland with the Republic of Ireland as a "workers' republic" adhering to Marxism-Leninism, leading to other Irish republican groups nicknaming the organization the "Red IRA". The group was responsible for the 1972 Aldershot bombing, its largest attack and the first major attack on mainland Britain during The Troubles. In May 1972, the Official IRA decided to declare a ceasefire and limit its operations to defense and retaliation, and the OIRA entered politics with the Workers' Party of Ireland, while the Provisional IRA outshadowed the OIRA militarily.